Multiple piston operated mud valve



June 19, 1956 R. R.-CROOKSTON 2,751,183 MULTIPLE PISTON OPERATED MUDVALVE Filed Oct. 23, 1952 E l5 I7 26 19 30 1/ 3/ i 2O 26 25 23 l3 4 I8 IX I; d 22 FIG. Ia E IIH I6 26 32 26 5O 23 I7 I l 5 \Q- E E Q /3 9' 25 2454 33 FIG. lb

I r I 20 II I /3/ 4O 7 4/ I2 22 f INVENTOR. 24 F/6 2 Robert R.Crooksfon,

BY m-./?,

AGENT and outlet. which protrudes through an opening in the wall memberlinto the second chamber. in the second chamber and is connected to thepiston arm. The second chamber is provided with separate United StatesPatent Ofiice 2,751,183 MULTIPLE PISTON OPERATED MUD VALVE Robert R.Crookston, Houston, Tex., assignor, by mesne assignments, to EssoResearch and Engineering Company, Elizabeth, N. J., a corporation ofDelaware Application October 23, 1952, Serial No. 316,396 4 Claims. (Cl.251-31) The present invention is directed to a by-pass valve. Moreparticularly, the invention is directed to a by-pass valve suitable foruse in drilling mud circulating systems.

'In its more particular aspects, the invention is directed to a by-passmud valve which is designed to open and close and eflect a positiveseal.

The present invention may be briefly described as infirst chamber.Arranged in the first chamber is a first piston which is adapted to openand close the inlet Connected to the first piston is a piston arm Asecond piston is arranged means for supplying operating fluid on eachside of the second piston for moving the second piston in two directionsin the second chamber and thereby opening and closing the inlet andoutlet by actuation of the first 1 piston.

It is required, in the device of the present invention,

fthat the first chamber be provided with an annular recess defined bythe housing which is adapted to receive an 'annular packing member.:municates with an exterior surface of the housing and with a source ofpressure lower than a pressure in the ffirst chamber defined by thehousing. Arranged in the recess is a deformable annular packing memberdefining a cylindrical surface and having a vertical circular cross-:section slightly greater than the depth of the recess. The "firstpiston is arranged to move into contact with the packing member and toform a seal therewith. The

The annular recess comarrangement of the recess with a passagewaycommunicating with a source of pressure lower than that of the pressurein the first chamber allows a seal to be effected without the annularpacking member being pulled out of the annular recess when the, firstpiston moves into contact with the packing member or engages ordisengages therewith.

It is also contemplated that the valve of the present invention willinclude in a second chamber a third piston which is arranged therein infree relationship to the second piston. The third piston is notconnected to the second piston but is provided with a guide means whichis slidably arranged in the housing to allow movement of the thirdpiston against the second piston and to move the latter.

The first piston and the piston arm may be constructed integrally and itis contemplated that the first I piston and the piston arm may definetherewith a cental bore allowing communication of the area in the firstthe drawing in which Fig. 1a is a sectional view of'a by-pass valveembodying the present invention showing the valve in the open position;

Fig. 1b is a similar View of the by-pass valve of Fig. 1a embodying thepresent invention with the valve in the closed position showing the sealeffected thereby; and

Fig. 2 is a modification of the embodiment of Figs. 1a and 1b.

In the several figures of the drawing, identical numerals will designateidentical parts.

Referring now to Figs. 1a and 1b, numeral 11 designates a valve housingdefining a central passageway 12 in which is arranged a piston shapedmember 13. Piston member 13 is bored to form a passageway 14 and isadapted to slide in the central passageway 12. Housing 11 defines achamber 15 in which is arranged a pair of pistons 16 and 17. Piston 17is threadably engaged with a guide rod 18 which slidably fits through aclosure 19 of housing 11. Piston 13 makes a sliding fit with wall member20 of housing 11 which defines, with closure 19, chamber 15. Housing 11defines a rectangular recess or groove 21 in which is arranged anannular packing member or O-ring 22 which may be constructed ofdeformable rubber, either natural or synthetic, plastic, an elastomer,or any other material which has tendency to extrude and flow underpressure. Recess v21 is in fluid communication with a collector groove23 which in turn fluidly communicates with a passageway 24 defined byhousing 11 and which opens .to the atmosphere or to a source of lowpressure. Central passageway 12, at its open end, is in fluidcommunication with a source of high pressure substantially aboveatmospheric or the source of pressure with which passageway 24 is incommunication.

The guide rod 18 is provided with suitable conventional packing rings 25to insure a seal thereof and the pistons 16 and 17 are similarlyprovided with packing rings 26, 27, and 28 to insure proper sealingthereof. Member 20.is also provided with a packing ring 29 to ;insure.aseal between piston 13 and member 20.

Referring now .to Fig. 2, it will .be seen that this is a modificationof Figs. 1a and 1b in that the piston 17 has been eliminated with itsallied parts, such as guide rod 18. Furthermore, it will be seen thatthe ,piston 13 of Figs. 1a and 1b has been replaced by the piston 40 .towhich is attached piston 16 by piston arm 41. It will be further notedthat piston 40 and piston arm 41 are not provided with a central boresuch as bore 14 of Figs. 1a and 1b.

With the elimination in Fig. 2 of the piston 17 of Figs. 1a and 1b theclosure 19 of Figs. la and 1b :has been replaced by the closure 42 ofFig. 2. This closure 42 is provided with an air inlet 31 defined byclosure 42 and the chamber 15 is provided with an air inlet 33. Theseparts are identical to the parts of Figs. 1a and 1b and function in asimilar manner.

The device of Figs 1a and lb may be connected a conduit 30 connected toa source of high pressure fluid, such as mud, under pressure in therange between 300 and 3000 p. s. i. g. Assuming that a stream of mud isflowing through conduit 30 into central passageway or chamber 12 and itis desired to close the valve embodying the apparatus, air underpressure would be admitted into the apparatus by way of a conduit, notshown, connected Patented June 19, 1956 allow the piston 13 to be ofconstruction itcannot do and the mud in chamber 12 in the path of piston13 b displaced through bore 14 into the space between pistons 16 and 17.When the piston 13 is to be moved to the right, air pressure is exerted.against piston 17 through port 33 which displaces the mud in the spacebetween pistons 16 and 17 into chamber 12.

Provision of the two pistons 16 and 17 also serves to held against or incontact with sealing member 22 by mud pressure exerted through bore 14against piston 16 which has a working area greater than that of piston13. Thus, after air pressure exerted against piston 17 has moved piston13 in contact with seal member 22 to, close the valve, mud pressureholds the valve closed. Pistons 16 and 17in cooperation with bore 14thus provide an easily openable and closeable valve and one that ismaintained closed by mud pressure. In other words, this is aself-closing feature. The pressure of mud in central passageway 12,however, would cause the O-ring or annular member'22 tore'main in the,recess or groove 21 since the force would be asserted diagonally acrossthe packing member and make the deformable packing ring seek to escapefrom its confinement through the groove 23 and passageway 24 since thispassageway communicates with a source of pressure lower than that of themud fluid. A positive seal would therefore be obtained.

When it is desired to open the valve defined by the apparatus shown inFigs. la and lb,'air or other'gasunder pressure would be admitted toinlet 33 defined by housing 11 and member 20 into chamber 15.. Thispressure would work against piston 16 which in turn would'mov'e ittoward piston 17 causing the mud in chamber 32 to be forced out throughbore 14 into the central passageway 12 as piston 13 is moved backward bythe force applied against piston 16; the outlet 34 would again be openedallowing the mud fluid to pass into central passageway 12 by conduit 30and outwardly therefrom by outlet 34 having a leading sloping surface34' allowing unimpeded passage of mud. As piston'13 moves into contactwith recess 21 containing annular member '22 "it would tend to pulltheannularmember 22 from its groove if the principle embodied in thepresent invention did not serve to maintain'the packing member22 inplace. Thus the deformable material or rubber wouldt'endto flow from therecess following the piston '13,but the pressure exerted by themud'fiuid in centralpassageway I2 is opposing this shearing 'force sincethe fluid and also the annular member 22 seek to escape by groove'23andpassageway 24 communicating with a source "oflow pressure. Thisopposing force effectively prevents the annular packing member frombeing pulled out from its recess '21 and thus being destroyed. The Oring 22etfectsaseal'while the piston 13 is being withdrawmresulting in'a snap action like that in popping open a bottle 'of champagne.

. Thus the forces to which the annular member is exposed would tend tocause it to be compressedor decreased in volume in view of Bournellfstheorem. Bournellis theorem is simply that, neglectingfrictiomthe totalenergy in a 'stream of fluid in any one directionfremains constant;therefore, when fluid flows through a restriction its velocity isincreased;. its kinetic energy is ,increased at cost, however, tothepotentialenergy. ,Stated more simply, the theorem is that where thevelocity is greatest'the pressure is :least. Thus; inthe device of thepresent invention in which a malerplug is :employed with a female O-ringto provide asealand-in' which the male .plug is removed, the superfluouspressure is released at the pointof breaking the seal and'thegpotentiahenergy is converted tovelocity energy and any positivepressure built up in the O-ring in the annulus containing-itteuds tocompress the O-ring which-bynature of vthejrna terial thus causes it toextrude very violently through This phenomena is regulariyisufieredinarrangemems recess 21 containing sun in the prior art such as a valvebody with an outlet in one direction only which is not symmetrical. Inthe present invention, however, the forces tending to eject the O-ringfrom its recess are overcome by allowing forces to be exerted diagonallyacross the O-ring tending to cause the O-ring to be extruded or seek tobe extruded through the passageway communicating to a pressure sourcelower than that of the pressure source exerted against the annularpacking member. It will be seen, therefore, from the foregoingdescription of the operation of the device bi -Figs. l'a-and lb that "an'improved sealing devicehas been described which'allows a positive sealat all times which obviatesdangers of the sealing member being pulledfrom a sealing position and destroyed.

The device of Fig. 2 operates similarly to the device of Figs. la andlb. Thus like in Figs. la and 1b the conduit 39 may be connected to asource of drilling mud under a high pressure, such as a pressure in'therange between 300 and 3,000 p. s. i.-g. As the stream of mudflowsthroughthe conduit 30 into chamber12 and it is desired to close thevalve, air under pressure would be admitted into the valve by way of aconduit, not'shown, connected to inlet 31 defined by the closure'42which would force piston 16 to the left and would cause the piston 40 tomove against the flow of mud fluid in chamber 12. As the piston 40 movesinto chamber 12, the mud ahead of it would bedisplaced and the piston 40would move into contact with the annular ring'22 forming a sealtherewith. The pressure of mud in'chamber 12, however, would tend tocause the O-ring orannular member 22 to remain in recess or groove 21since force would be asserted diagonally across the packing member andmake the deformable packing member seek to escape from? its confinementthrough the groove 23 and passageway .24. Sincethis latter passagewaycommunicates with a source of pressure lower than that of .the mudfluid, a positive seal would be obtained.

When it is desired to open the valve, air or other gas under-pressuremay be admitted to inlet 33, by a conduit not shown, defined by thehousing 11 and the wall member 20 into chamber 15 ahead of the piston16. This pressure works'against piston 16 and would move it to the rightcausing the air back .offthe piston 16 to be forced out through thepassageway 31. i The outlet 34 would be again opened allowing mud fluidto pass into chamber 12 by conduit 30 .andoutwardly therefrom I byoutlet 34. As the piston 40 moves in contact with lar member 22 it would.tend to pull'the annular member 22 fromits groove :if force were notasserted across the annular member 21 by the mud pressure in chamber 12.Otherwise the annular member' -22 would tend to lflow from the recessfollowing the piston. Thus in accordance with-this modification of thedevice of my invention a positive sealing effect is obtained. The valveis either inthe completely open or closed position.

It is tobe understood that when operating ifluid is being admitted by(inlet 31 in the case of Fig. 2,-'air or :operating fluid-admitted byinlet 33 would be forced outwardly through inlet .33 andareleasedthrough means not shown, lhe same applies whenair or gas 'is admitted byinlet 33; in this case, the air :admitted by inlet 31 would be forcedout .therethrough and also released throughmeans not :ShOWIl.

It may be noted with regard to the'two embodiments .of

. the drawing thatpiston13has a working area less than the working areafof-ithe piston any. section I of ,the iopening in which there-areplusor minus .ditferencesi inskinetic'fenergy.

that of the working area of pistons 16 and 17 and that 40 ,is less thanthat .of-the :piston 16. .It is possible, therefore, to overcome the:mud pressure asserted on pistons 13 ,and 40-.by air pressure less than.thatof themud pressure.

I he invention :has tbeen-xlescribedaud illustrated with one passagewaycommunicating thezrecess withazsource be understood that'thispass'age'way may be a plurality of passageways. In fact, it is preferredthat a plurality of passageways be employed such that the O-ring ordeformable annular packing member will seek to be extruded through theplurality of passageways and thus be held snugly in the groove or recessprovided for it. It will be seen that positive forces are trying toextrude the O-ring to the outside of the valve housing via the weepingannulus or bleeder holes which means the O-ring is always held in place.When the seal is about to be broken as described and illustrated by thefirst piston member, these forces, explainable by the phenomena relatedto Bournellis theorem, tend to cause the rubber O-ring to stretch,changing it from approximately circular cross section with little or nopressure on it to a rather elongated ellipse, the degree depending uponthe differential pressures involved. The major axis of the O-ringextends from the weeping annulus to the escape annulus. The fact thatthe O-ring is under tension and distorted from circular cross section toelliptical, causes the ring to snap back into place by effect of theforce of higher pressure across the O-ring, causing it to seek to escapethrough the Wceper holes. The ring is under tension and distorted fromcircular cross section to elliptical, causing it to snap back into placeso that the rate of effective opening depends not only on the rate ofpiston travel but also on the rate of spring back of the O-ring itself.This snap action action actually reduces the total abrasion suffered bythe O-ring and seat material in applications such as described withrespect to Figs. la and 1b where the surfaces are in contact withabrasive fluid, such as mud.

When the first piston is closing and is about to enter the locus of theO-ring, negative or zero pressures exist (again explainable byBournellis theorem) and the ring tends to jump up to meet the piston,thus also atfording an increase in the rate of closure with a benefitsimilar to that attained in snap action opening, namely, reduction inabrasion. These fast openings and closings minimize erosion of themetallic and rubber parts and are important advantages in the handlingof abrasive materials, such as drilling mud.

Thus, from the foregoing discussion it will be seen that it isimpossible for the first piston to shear the O-ring by impinging itagainst the edge of the opening annulus. Hence the forces opposing theO-ring to leave this recess overcome the tendency of the forces strivingto remove the O-ring from the recess. In short, the pressure from thehigh pressure source seeks to escape to the low pressure source and thiscauses the O-ring to remain in its groove designed for that purpose.

The valve of the present invention is advantageous in that it forms apositive seal and in that it is either in the open or shut position andwill allow the by-passing of abrasive fluids, such as drilling mud, withminimum .erosion of exposed parts.

This application is a continuation-in-part of Serial No.

'10 ,737, entitled Valve Sealing Device, filed August 5, 1949, or RobertR. Crookston, which matured into Patent 1N0. 2,722,402 on November 1,1955.

The nature and objects of the present invention having 1 been completelydescribed and illustrated, What I desire to claim as new and useful andto secure by Letters Patent .iS'

1. A mud valve which comprises a housing provided 'with a wall memberdefining with said housing first and :second chambers having an inletand outlet for said first chamber, a seating surface provided by saidhousing in longitudinal axis perpendicular to the longitudinal axis ofthe inlet for smooth and uninterrupted flow of mud from the inlet to theoutlet through said chamber, a first piston arranged in said firstchamber adapted to close and third pistons in said second chamber andthereby closing and opening said inlet by actuation of said firstpiston.

2. A mud valve which comprises a housing provided with a Wall memberdefining with said housing first and second chambers having an inlet andan outlet for said first chamber, a seating surface provided by saidhousing in said first chamber between the inlet and outlet, said inlethaving a common longitudinal axis with said first first pistonprotruding through an opening in said wall member into said secondchamber, said first piston and said piston arm being provided with acentral bore communicating the first chamber ahead of said first pistonwith working area greater than the working area of the first pistonrigidly mounted on said piston arm intermediate its ends, a third pistonin said second chamber on the side of said second piston remote fromsaid first piston and in slidable free relationship to said secondpiston having a working area greater than the working area of the firstpiston, and separate means for supplying clean operating fluid to theopposite ends of said second chamber to move said second piston to theright and to move said second and third pistons to the left and therebyopening and closing said inlet by actuation of said first piston.

3. A mud valve which comprises a housing provided with a wall memberdefining with said housing first and second chambers having an inlet andan outlet for said first chamber, an annular seating surface provided bysaid housing in said first chamber between the inlet and outlet,

the inlet, a second piston in said second chamber having itsends,athird; pistoninsaid second chamber oni theside of said secondpistoni'r emote irom said .firstxpiston and inslidable-free relationshiptosaid second pistonihaving a working areagreater than the working area.of the first piston, a guide rod attached to said third piston slidablyarranged in an exterior wall of said valve housing, andseparate meansfor supplying clean operating fluid to the opposite ends of said secondchamber .to move said-second piston to the right and to move said secondand third pistons to the left and thereby opening and closing saidinletby actuation of said first piston.

4. A mud valve which comprises a housing provided witha wall memberdefining withsaid housing :first and second chambers having an inlet andan outlet for said first chambenan annular seating surface provided bysaid housing in said first chamber between the inlet and outlet, saidinlet'having aicommonlongitudinal axis with said=first chamber andlsaidzoutlet beingarranged. in said housing downstream frornsaid seatingsurface and having its longitudinal axis. perpendicular tothelongitudinal axis of the inlet and providing a leading slopingsurface for smooth and uninterrupted flow of' mud, a first pistonarranged in said first chamber adapted to close and open said inlet byslidable movement along the longitudinal axislof the first chamber intoand out of contact with said seating surface, a piston arm connected tosaid first piston protruding through an opening in *said wall memberinto said second chamber, said first pistonand said piston arm beingprovided with a central bore communicating the first-chamber ahead ofsaid first piston with the second chamber-for How of .mud into saidsecondvchamber pn movement-ofsaid firstrpiston to close the inlet, asecond piston insaid second chamber :having a working areagreaterthanthe working area of the. first piston rigidly mounted on saidpiston. arm intermediate; its ends, athird piston insaid .secondchamberon;the side. of .said second pistonremote from saidfirst piston and inslidable free relationshipto said. second piston having a working areagreater than the 'workingt'area of the ,first piston, and separate meansfor supplying clean operating fluid to the opposite-ends of said-secondchamber to move said second piston-to the rightand to move said secondand third pistons to the left and thereby openingand closing saidinlet'rby actuation of said first piston.

References Cited in the fileof this patent UNITED STATES PATENTS

